1. Field of the Invention
The present invention relates to novel pseudoceramides and cosmetic compositions comprising the same. More particularly, the present invention relates to novel pseudoceramides showing excellent permeability barrier similar to that found in natural ceramides and improved water solubility and cosmetic compositions comprising the same as active ingredient.
2. Description of the Related Art
The stratum corneum, which is located on the outermost side of the skin, serves a primary protection barrier from external irritation and invasion of foreign substances and maintains the moisture in the skin through intercellular lipids.
The intercellular lipids comprise ceramides, cholesterol, free fatty acids and neutral lipids, etc. and it has been found that ceramides is contained in the amount ranging from 40 to 50% and the most pivotal lipids in the intercellular lipids. It has been reported that the decrease of ceramide production caused by some genetic factors or aging is responsible for the weakening of barrier function of stratum corneum, thereby leading to adverse effects on the skin, e.g. atopic dermatitis and psoriasis (Fulmer & Kramer, J. Invest. Derm., 86:598-602(1986); and Tupker R. A. et al., Acta Derm. Venereol. Stockh, 70:1-5(1990)).
Under such circumstances, many researches have focused on development of process for preparing natural or synthetic ceramides with greater efficiency and of novel pseudoceramides. The conventional process for preparing ceramides includes extraction method (from animal, plant or yeast) and chemical synthetic method.
Naturally occurring ceramides show superior function but inferior application to cosmetic compositions due to lower solubility, finally resulting in high production cost.
Therefore, there remains a need in the art for novel synthetic ceramides with excellent water barrier function, exhibiting improved applicability to cosmetic composition, which can be synthesized at relatively low cost.
U.S. Pat. No. 5,206,020 discloses novel synthetic pseudoceramide prepared by ring opening the epoxide ring of a glycidyl ether with RNH2 to yield the corresponding secondary amine and then acylating the secondary amine. In addition, U.S. Pat. No. 5,175,321 discloses novel pseudoceramide synthesized in such a manner that certain compound prepared from glycidyl ether and ethanolamine is reacted with a fatty acid lower alkyl ester.
Throughout this application, various patents are reference and citations are provided in parentheses. The disclosure of these patents in their entities are hereby incorporated by references into this application in order to more fully describe this invention and the state of the art to which this invention pertains.